Differentiating surface and bulk interactions in nanoplasmonic interferometric sensor arrays. Issue 1 (12th November 2014)

• Record Type: Journal Article
• Authors: Zeng, Beibei; Gao, Yongkang; Bartoli, Filbert J.
• Is Part Of: Nanoscale. Volume 7:Issue 1(2015)
• Page Start: 166
• Page End: 170
• Publication Date: 2014-11-12
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c4nr05495d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : A nanoplasmonic interferometric sensor is demonstrated to differentiate the protein surface layer from bulk solution changes at a single spot. Abstract : Detecting specific target analytes and differentiating them from interfering background effects is a crucial but challenging task in complex multi-component solutions commonly encountered in environmental, chemical, biological, and medical sensing applications. Here we present a simple nanoplasmonic interferometric sensor platform that can differentiate the adsorption of a thin protein layer on the sensor surface (surface effects) from bulk refractive index changes (interfering background effects) at a single sensing spot, exploiting the different penetration depths of multiple propagating surface plasmon polaritons excited in the ring–hole nanoplasmonic sensors. A monolayer of bovine serum albumin (BSA) molecules with an effective thickness of 1.91 nm is detected and differentiated from a 10 −3 change in refractive index unit for the bulk solution. The noise level of the retrieved real-time sensor output compares favorably with that of traditional prism-based surface plasmon resonance sensors, but is achieved using a significantly simpler collinear transmission geometry and a miniaturized sensor footprint.